This Swiss made watch case opener will open most waterproof watch cases. Includes four sets of different type of chucks, chucks will work on polygonal, slotted, hole, and grooved case back. Made of high quality steel to help form a tight grip when removing the metal caseback from waterproof watches. Because this tool is metal, it may have additional grease around joints to prevent rusting and ensure smooth operation when adjusting tool. Comes in a red plastic case to hold all of the parts in one convenient place.